Multiple, as opposed to single impairments are major contributors to falls and increased functional dependency. Examples of these impairments include visual, leg strength, and cognitive impairment. The effect of these impairments is magnified as the demands of a functional task increase. Furthermore, adding more impairments frequently yields a disproportionate increase in disability. Little is known regarding how combinations of impairments contribute to functional disability. Little is known regarding how combinations of impairments contribute to functional disability. Little is known regarding how individuals compensate for their impairments. Our Program data to date suggests that studies of other tasks and techniques are necessary to help explain the complex relationships among impairments, functional task demand and actual task performance. In this Project, we propose a more specific, controlled, and quantitative experimental approach as the next logical step. The goal of this study is to determine how losses in capabilities (strength, visual, and cognitive impairment) affect mobility-task performance (walking speed and stepping accuracy), particularly when mobility-task demands (increasing strength, visual, and cognitive demands) increase. We will study adults aged 60 and other with specific impairments: individuals who have, either singly or in combination, cognitive impairment, visual impairment, and lower extremity weakness. We chose these impairments based on their contribution to disability, falls, fall-related injury, and institutionalization. These individuals will perform walking-related tasks that provide increasing challenge, particularly with respect to their existing impairment. These tasks simulate a number of walking challenges that might be encountered daily by many older adults (such as stepping accurately to avoid an obstacle or slippery surface). These data will suggest the degree to which impairment must be decreased and/or task demand decreased in order to reduce real world functional disability.